Still chasing the stumbling problem on the SL, but (again) think it is about to be run to ground. The car is now with a former MB mechanic who is branching out onto his own here in Fort Walton Beach, FL.

Briefly, have replaced the following: fuel pump/filter/accumulator, injectors (along w/seals and holder, fuel distributor, idle air hoses and probably a couple other things I don't recall. Turns out that the WUR/fuel pressure regulator is not "warming up". The mechanic has also figured out that some of the vaccum lines are run incorrectly (probably from the previous mechanic when he changed the idle air hoses and trying to troubleshoot). There are also two lines running under the throttle body that he says have no vacuum.

He's going to pull the throttle body to troubleshoot the lines with no vacuum and will replace the air duct housing the throttle body sits on while running the vacuum problem to ground. He seems to be relying on "what looks/works right", along with a diagram from an '83 model. Don't know if this model is SL/SEC/SEL.

He's quoted me a top price of ~$1,500-$2,000 for the work, which includes parts. (Says when he worked at Quality Imports he got 12-14 hours labor--@$ 99.69/hr for the job.) He seems honest, relishes the challenge and is charging $55.00 an hour since he has no overhead when working out of his garage at the house while his shop is being built. Sounds like a decent price for all that is being done, especially since it seems the previous mechanic who had the car for about two months and put in quite a few hours messing with it is only going to charge a couple hundred for his time and frustration.

I've searched eBay on occasion and only seen one manual for the 117.962 engine ever come available. I bid up to about $150.00, but didn't get it.

If any of you guys with the Euro 500SL happen have a vacuum diagram that you can share, it would be greatly appreciated.

I don't like to be in the position of coming between an man and his mechanic, but 12-14 hours is way too much for this job. I think 4-5 hours is hugely generous. You need to remove all the lines from the fuel distributor, and get them out of the way,which means that you may have to unscrew some from the injectors. Then you loosen the clamp that holds the rubber air channel to the mixture control unit, undo four nuts and lift the mixture control unit off. Hook up the vacuum lines and reassemble in reverse order. I did this on a 380 when I knocked a line off pulling one of the heads, and even with my fumbling and bumbling, it took about four hours.

Alldata doesn't show a job for the mixture control unit, but the R/R for the whole intake manifold, which is a MUCH larger job is 6.7 hours.

I appreciate the insight on the time factor. However, there has been much more involved in this job than just the R/R. I spent three hours in his garage yesterday afternoon while he was troubleshooting the problem. He had just finished a compression check on all of the cylinders before I got there and said they couldn't be any better than what they showed.

He continued to work on tracking down the rich fuel problem while I was there. He pulled all of the injectors and popped them. The four on the right side, which is the side running rich, were all clogged. The left side popped fine.

In the process, he put the injectors back on the fuel lines and left the pasenger side injecotrs out of the engine. He then bypassed the starter to make the fuel pump run. Whereas the injectors should not have been putting any fuel through them, they were putting out a steady stream. We went thrugh two or three iterations before moving on to the fuel distributor itself.

It took thirty minutes just to loosen the three screws holding the FD on. The previous mechanic must have used an air gun to screw them in and he didn't want to break one off or stip the head. When he got the screws out and lifted the FD up (with the fuel lines/injectors still attached) an o-ring on which the FD should have seated popped out. It had been cut and there was about 3/8" of it missing. He surmises the FD was not seated properly and the passenger side was cocked, not letting the plunger seat fully and allowing fuel to continue to flow to the injectors after the engine was shut off--which was clearly the case. This also created a vacuum problem which only added to the problem.

There is still the problem of the vacuum lines going under the throttle body needing to be tracked down and that is why he is pulling the FD and throttle housing off. Not to mention that since we have gone this far we may as well go ahead and replace the air flow unit the thing sits on.

In addition, he has spent time redoing the vacuum system and also troubleshot and replaced the Warm Up Regulator/Fuel Pressure Regulator. He's put a fair amount of hours into the project and has a few more to go before all is said and done. So, I suppose I should have been a little more detailed in what the $1,500-$2,000 bucks actually included.

I should probably be looking at recourse to the previous mechanic, which is what he suggested. Fortunately, I've not paid the previous guy who contributed significantly to this mess anything yet. There are some things I legitimately owe him some money for and I'm sure he'll take all that has transpired into account when I settle up with him.

Looking back, it is very likely that my both the FD and WUR were bad and were the cause of the initial problems I set out to fix. Had I taken the car to the dealership and let them put the CIS tester on it, I could have probably saved myself some time and (perhaps) some dollars. I chose to go the cheaper route and relied on some people who were not up to the job. I should have realized this myself, but I didn't. I brought some of this on myself and accept responsibility for that.

Ultimately, I will have about $3,000 bucks in this repair job. But I now have completely rebuilt fuel and vacuum systems. There ought to be a lot of trouble free miles ahead in the SL. Additionally, I have learned a HECK OF A LOT more about this car than I ever envisioned I would know.

As an aside, I have a different perspective on things since having cancer last year and decided that I would channel my energies toward enjoying life and not letting the small stuff get next to me. I consider this some of the small stuff.

Don't get me wrong, I don't appreciate having to spend a fairly large sum of money to run this problem to ground. I'm not a rich man, but I am very wealthy. This experience has added quite a bit to my knowledge and provided some lessons that I can pass along.

Glad that you're getting good work from a guy who sounds quite competent. I was reluctant to write that last post but decided to because from your initial description of the work, it looked like a large rip-off.

If nothing else comes of this experience, I have found a very good MB mechanic in the area. It's very unlikely that I would have encountered him on my own as his advertisement is low key and mainly by word-of-mouth--at least until he gets into his garage in Feb.

If all goes as planned, I'll be going to church in Falls Church this weekend with my daughter and her family.